1. Field of the Invention
This invention relates generally to the use of an image-sensing device in connection with a wireless communication device in conjunction with a location determination element.
2. Related Art
The worldwide utilization of wireless devices such as two-way radios, portable televisions, personal communication system (“PCS”), personal digital assistants (“PDAs”) cellular telephones (also known a “mobile phones”), Bluetooth, satellite radio receivers and Satellite Positioning Systems (“SPS”) such as Global Positioning Systems (“GPS”), also known as NAVSTAR, is growing at a rapid pace.
When emergencies occur, people are used to dialing 911 (normally referred to as a “911” call) on a land telephone and contacting an emergency center that automatically is able to identity the location of the land telephone where the call originated. Typically, wireless devices are unable to communicate their location without a person entering or describing their location. The United States Congress, through the Federal Communications Commission (FCC), has enacted a requirement that cellular telephones be locatable to within 50 feet once an emergency call, such as an “Enhanced 911” (also known as E911), is placed by a given cellular telephone. This type of position data would assist police, paramedics, and other law enforcement and public service personnel, as well as other agencies that may need to have legal rights to determine the position of specific cellular telephone. The “E911” services, however, operate differently on wireless devices than a 911 call does on land-line telephones.
When a 911 call is placed from a land-line telephone, the 911 reception center receives the call and determines the origin of the call. In case the caller fails, or forgets, to identify his or her location, the 911 reception center is able to obtain the location from which the call was made from the public telephone switching network (PSTN) and send emergency personnel to the location of the call.
If instead, an E911 call is placed from a wireless device such as a cellular telephone, the E911 reception center receives the call but cannot determine the origin of the call. If the caller fails, or forgets, to identify his or her location, the E911 reception center is unable to obtain the location of the call because the wireless network is different than the PSTN. At present, the best that the E911 reception center may do is to determine the location of the cell site from which the call was placed. Unfortunately, typical cell sites in a wireless network system may cover an area with approximately a 30-mile diameter. Further refinement of the location may be determinable in a digital network by the power setting of the calling wireless device. But, this still results in an area covering multiple miles.
A proposed solution to this problem has been to utilize a wireless positioning system that includes satellites and/or pseudolites (such as base station) to triangulate the position of a wireless device such as a cellular telephone. GPS is an example of a Satellite Positioning System (SPS) that may be utilized by a wireless device in combination with an appropriate GPS receiver to pinpoint the location of the wireless device on earth. For example, U.S. Pat. No. 5,874,914, issued to Krasner, which is incorporated by reference herein, describes a method wherein the base station transmits GPS satellite information, including Doppler information, to a remote unit using a cellular data link, and computing pseudoranges to the in-view satellites without receiving or using satellite ephemeris information. Another proposed solution requires multiple displays and transmission of location data and image data to a receiving device without being associated. For example, U.S. Patent Application No. 200020077123 A1, applied for by Shuji et al., which is incorporated by reference herein.
The array of GPS satellites in a SPS transmits highly accurate, time coded information that permits a receiver to calculate its exact location in terms of latitude and longitude on earth as well as the altitude above sea level. The GPS system is designed to provide a base navigation system with accuracy to within 100 meters for non-military use and greater precision for the military (with Selective Availability ON).
The space segment of the GPS system is a constellation of satellites orbiting above the earth that contain transmitters, which send highly accurate timing information to GPS receivers on earth. The fully implemented GPS system consists of 21 main operational satellites plus three active spare satellites. These satellites are arranged in six orbits, each orbit containing three or four satellites. The orbital planes form a 55° angle with the equator. The satellites orbit at a height of 10,898 nautical miles (20,200 kilometers) above earth with orbital periods for each satellite of approximately 12 hours.
Each of the orbiting satellites contains four highly accurate atomic clocks. These provide precision timing pulses used to generate a unique binary code (also known as a pseudo random or pseudo noise “PN” code) that is transmitted to earth. The PN code identifies the specific satellite in the constellation. The satellite also transmits a set of digitally coded ephemeris data that completely defines the precise orbit of the satellite. The ephemeris data indicates where the satellite is at any given time, and its location may be specified in terms of the satellite ground track in precise latitude and longitude measurements. The information in the ephemeris data is coded and transmitted from the satellite providing an accurate indication of the exact position of the satellite above the earth at any given time. A ground control station updates the ephemeris data of the satellite once per day to ensure accuracy.
A GPS receiver configured in a wireless device is designed to pick up signals from three, four, or more satellites simultaneously. The GPS receiver decodes the information and, utilizing the time and ephemeris data, calculates the approximate position of the wireless device. The GPS receiver contains a floating-point processor that performs the necessary calculations and may output a decimal display of latitude and longitude as well as altitude on the handset. Readings from three satellites are necessary for latitude and longitude information. A fourth satellite reading is required in order to compute altitude.
These techniques, however, still do not perform well in dense environments where the location of a wireless device (such as a cellular telephone) is usually hindered in dense environments such as downtown city blocks. A SPS system within the wireless device should have the capability to acquire and track the SPS satellites under the conditions that the typical user of a wireless device will encounter. Some of these conditions include utilization of the wireless device indoors and in dense urban areas that have a limited sky view, such as in downtown areas with skyscrapers blocking the views of the normally available satellites, etc. While these environments are typically manageable for terrestrial-based wireless communications systems, they are difficult environments for a SPS system to operate. For example, traditional “autonomous mode” SPS systems (i.e., SPS systems where the SPS receiver acquires the signals from the SPS satellites, tracks the satellites, and, if desired, performs navigation without any outside information being delivered to the SPS system) have problems with long Time To First Fix (“TTFF”) times and, additionally, have a limited ability to acquire the SPS satellite signals under indoor or limited sky-view conditions.
Even with some additional information, TTFF times may be over thirty seconds because the ephemeris data must be acquired from the SPS system itself, and the SPS receiver typically needs a strong signal to acquire the ephemeris data reliably. These characteristics of a SPS system typically impact the reliability of position availability and power consumption in wireless devices. Typically, the accuracy of location-based solutions may vary from 30 meters to 300 meters in these types of environments. As a result locating a wireless device in a 300 meter radius zone is unlikely unless there are other methods to help narrow the search. Other location-based solutions may include network based location approaches such as Advance Forward Link Triangulation (AFLT, Cell ID, Enhanced Cell ID)), Angle of Arrival (AOA), Time of Arrival (TOA), and Enhanced Observed Time Difference (EOTD). Thus, location determination approaches include not only SPS system, but also network based location approaches.
It can be seen, then, that there is a need in the art for a method of sending additional surrounding information to more accurately locate the wireless communication device. It can also be seen that there is a need in the art for sending images with user position data to assist police, paramedics, and other law enforcement and public service personnel, as well as other agencies that may need to have legal rights in determining the location of a wireless device.